Managed care, ranging from health maintenance organizations (HMOs) to preferred provider organizations (PPOs), has become the predominant form of private health insurance in the U.S. The main objective of this study is to further understand how alcohol services are provided in HMOs, one of the earliest and most common forms of managed care. We build on round 1 of our national survey of managed care organizations (MCOs) regarding alcohol service provision in the 1999 benefit year. The specific aims are to: 1. Describe the provision of alcohol services in HMOs for the 2003 benefit year in terms of both administrative factors (including overall plan characteristics, contracting arrangements, payment methods and risk sharing, and benefit design) and clinical factors (including treatment approaches, utilization management, provider selection, entry into treatment, and quality assurance). 2. Document how the provision of alcohol services in HMOs has changed over a four-year time period, and explore what factors influence these changes. 3. Model why some HMOs provide alcohol services internally within the plan and other HMOs choose to carve out alcohol services to specialty managed care vendors. In round 1, we surveyed a sample of MCOs stratified by type of product offerings (HMO vs. PPO) in 60 market areas with NIAAA funding the HMO and NIDA funding the PPO portions of the study. We surveyed 434 MCOs in round 1, including the 283 MCOs that reported HMO products, and achieved a 92 percent response rate. We will conduct round 2 of a telephone survey of these 434 MCOs, as well as a refresher sample in theses 60 market areas regarding their HMO products. Companion funding has already been obtained from NIDA to conduct round 2 surveys of these same MCOs regarding their PPO products. We will continue to collaborate with longitudinal, nationally representative Community Tracking Study (CTS) conducted by the Center for Studying Health Systems Change which provides the sample frame of health plans in the 60 market areas. The proposed study of alcohol treatment services is the first to combine two rounds of a national survey of MCOs within market areas in a prospective design that will allow us to track how the delivery of alcohol services in HMOs evolves within the changing health care market. These changes include: expansion of federal and state substance abuse parity legislation; increased enrollment in behavioral health specialty vendors; increased managed care regulation, particularly state consumer protection laws regarding managed care; and treatment innovations including the approval of naltrexone. This study will provide systematic information on the nature and extent of HMO changes, and their impact on alcohol service delivery, during this time period.